I need to update acrobat standard 6.0.6 to 7.0.0

I've got Acrobat Standard 6.0.6 on an old work computer, so I tried to update it. I found updates on adobe's site all the way from 7.1 to 11.0. Is there any way I can get up to 7.0.0? Perhaps it requires an actual upgrade to go up to the next major version release? I spoke with customer support, but I could find a serial number b/c I have no original documentation and couldn't guess the email address it was registered to, so he wouldn't help me.

Aside from what Karl answered you do want to be aware that all Acrobat versions prior to Acrobat 9.x have past into the End of Support bone yard and are no longer available from Adobe. In May of this year Acrobat 9.x joins them. What is available from Adobe is Acrobat XI..Be well...